This project is designed to provide essential information necessary for a sound scientific basis for the evaluation of adjuvants utilized in the production of antibodies in laboratory animals. Adjuvants are believed to enhance the immune response of animals to immunogens primarily by two mechanisms; 1) the depot effect whereby the water in oil emulsion prevents rapid degradation of the immunogen and 2) by invoking an intense inflammatory response enhancing macrophage and helper T-cell processing of the immunogen. These two mechanisms also result in localized tissue destruction and severe inflammation which would likely result in some degree of pain and distress in the injected host animal. A sound scientific basis for recommending a proper methodology for the utilization of Freund's complete adjuvant (FCA) is lacking. Recommendations from various sources differ on acceptable routes of administration and vary widely on the recommended maximum dose per site. Establishment of the most efficacious route of administration of FCA and maximum volume per injection site for the production of antibody that also results in the minimal amount of tissue destruction and resulting pain and distress is the specific aim of this project. While limited in scope, this project provides the necessary data to permit a scientifically sound basis for future investigations of new and innovative adjuvants which will inevitably be compared to FCA. Nine experimental treatment groups of 5 rabbits will be injected with Freund's Complete Adjuvant and mouse IgG (1: 1) . The total dose per rabbit will be 0. 5 ml containing 100 (mu)g of mouse IgG. The routes of administration and the volume injected per site will vary among the groups. Routes of administration include intramuscular, intradermal, and subcutaneous. The volume per site varies in such a way as to evaluate the range of recommendations present in the literature. Antibody response will be evaluated by ELISA with both specific IgG and IgM being determined. Following a subcutaneous booster in PBS at 10 weeks post-injection, the secondary immune response will be similarly determined. Lesion quantitation will be done non-invasively by caliper measurement for intradermal injections and by ultrasound examination for subcutaneous and intramuscular sites. Local inflammatory response will be evaluated by radiolabelling of homologous leukocytes and radioimaging. Final lesion evaluation at 14 weeks post-injection will be done by necropsy and histopathology.